A lonely dolphin that experts say is possibly sexually frustrated is believed to be behind a spate of attacks along the beaches of central Japan.
Dolphin attacks have left more than 45 people injured in Wakasa Bay, nearly 200 miles (320km) west of Tokyo, since 2022, with most of the recent ones occurring near the towns of Echizen and Mihama.
After examining photos and videos of some of the attacks from 2022 and 2023, experts concluded that they involved the same male Indo-Pacific bottlenose dolphin.
The same animal could be behind this year’s attacks, said Ryoichi Matsubara, director of the Echizen Matsushima Aquarium in Fukui, although he hasn’t reviewed more recent footage yet, The New York Times reported.
The dolphin might be displaying mating behaviour, he said, noting that it was seen attempting “to press his genitals against people” in 2022 and 2023. He added, however, that many injuries occurred as beachgoers approached or tried to touch the dolphin.
Putu Mustika, a marine researcher at James Cook University in Australia, told the newspaper that “dolphins, when they are mating, can be very wild”.
She said that lunging on top of a human could be a sexual act and a sign that this was a “horny, lonely dolphin”.
Ms Mustika noted that the dolphin might naturally be aggressive and grow irritated when people try to touch it.
Tadamichi Morisaka, a cetology professor at Japan’s Mie University, told the BBC: “It is reasonable to assume that it’s the same individual as the wounds on the tail fin are similar to those of the dolphins seen off the coast last year, and it is rare for dolphins, which normally move in groups, to be alone for such a long time.”
A bottlenose dolphin named Moko gained fame in New Zealand in the 2000s for its playful behaviour with swimmers, although it occasionally acted in unsettling ways, like preventing a woman from getting back to shore. In 2018, a French town temporarily banned swimming after a male bottlenose dolphin named Zafar began displaying sexual behaviour by rubbing against swimmers and boats.
Japanese authorities have tried several measures to deter people from getting close to dolphins and to prevent dolphin attacks. They have installed underwater acoustic devices that emit high-frequency sounds to keep the dolphins away, and put up warning signs and distributed flyers cautioning beachgoers that dolphins can bite or drag swimmers into the sea.
They have also reduced swimming hours at some beaches and increased lifeguard patrols.
A few years ago, marine expert Tetsuya Matsuoka, who manages the Notojima Aquarium in Nanao, told Asahi Shimbun: “People have this image of dolphins as cute creatures, but they are wild animals after all. You should not go near them or touch them because they have sharp teeth.”